Lining for conduits



July 7, 1925.

T. E. MURRAY LINING FOR CONDUITS Filed Aug. 9; 1923 70 o M o n a THO/W5 E Mummy Patented July 7, 1925.

- UNITED YP'IATENT:OFFICE?- rHoMAs E.- MURRAY, or BROOKLYN, Ni wxoRK.

i A ram filed August 9} 1923'. Serial no. 656,573.

To all whom, it may concern.

Be it known that I, THO AS E. MURRAY, a. citizen of theUnited States, and resident of Brooklyn, Kings County, "Stateof New York, have'invented' certain new and useful Improvements in Linings for Conduits, of which the following-is afspecification;

In several prior patents of Thomas E.

Iiflurray, particularlyPatent No 1,387,0i66 of- August 9', 1921.,tl1'ere are described methods and-devices for molding pipes and'similar hollow structures-of plastic material, as cement or the, like;

The prior vMurray patents are based on the use of a core which after the cement has hardened, is collapsedand withdrawn f In the above identified prior patent, there is described a wire enclosingthe core and adapted to lie-used for withdrawing the core longitudinally from I the molded conduit. Said patent also shows an inner wire coreon which a sheetfof flexible,material such as paper is wound;

p The present like which is adaptedto remain in the conduit permanently that is, it is not w1thdrawn as in the prior Murray patents.

here conduits of greatlength are constructed as, in street, pavements, and where there IS considerable moisture absorbed by:

the cementitious material forming the con duit, an ordinary paper lining would have several disadvantages. the paper became softened and electrical conductors were fished therethrough, the paper would be distorted and in time would clog the conduit and prevent fishingor threading conductors therethrough.

The present invention contemplates proriding a waterproof coating for the paper lining so that'it will be practically impervious to moisture and also contemplates proriding a reinforcement for the paper tube or'lining which will prevent it from sagging inward when moisture reaches the same due to imperfections or removal of the waterproof. coating.

The accompanying drawings illustrate embodiments of the invention. 1

Fig. 1 is a longitudinal section through a pipe or conduit having an inner lining of 7 paper or similar fibrous or flexiblematerial mnnveroia con'nuirsq nventionis'in part a con-' tinuation and in part an improvement on.- the inventions disclosed in the priorMurray patents, and contemplates providing a-pi'pe or conduit havinga lining'of paper orthe For example, when FigJ-Q 'is'asimilar view showing'an alternatlve form of reinforcement for the lining;

3 is an enlarged view of the core showing a layer 'of waterproofing material on the inner surface thereof;

Fig-'4 isa similar view showing a core waterproofed both on its inner and outer '-surfaces. v a 7.

The core 10 'is preferably made of flexible or fibrous material suchas paper or card.-

board whichcan be commerciallyproduced inv'ario'us ways, for example, by winding "either single or superposed strips of paper or cardboard on a JDHIlClIGli Such tubes can-be made of varying thicknesses soas to have greater 'or less rigidity of flexibility,

but inorder to produce a commercially practicalcore or lining for-conduits, it is preferable to use-a minimum amount of paper so as to keep down :the cost.- This means that the core wall m-ustbeof comparatively thin, {cross section. To prevent such thinfpaper tubing from collapsing when handling the core and also when casting material around it, I provide a. spirally wound reinforcement 12preferably infthe form of a flat strip, as

shown in Figs. '1' and 3, this strip having prongs 14. which bite into the fibersof the paper tubing 10,

The core 10 is adapted to form a permanent lining for a-pipe or conduit which as illustrated in Fig; 1 is formed of a layer of co ientitious material 16, which is molded g-aroundthc exterior of the core and allowed to set.

The core 10 forms a smooth inner lining for the conduit and preferably has applied to its inner and outer surface a layer of waterproofing material 18 and 20, best shown in Figs. 3 and 4. The waterproofing layers 18 and 20 may be of cloth impregnated with suitable moisture resisting compound such as tar, parafl'm or the like, or these moisture or water resisting elements may be of paper which is shellaclred or varpaper liningsas shown and described are.

' well. adapted foruse in? the walls and dooring of :building structures where :there is not presenta great deal of moisturesuch as 1 below street pavements, tunnels, ==subways and similar undergroundstructures. 7

As best'Tshown-in Fig. Mi -the outer-reinforcement 12'is a'flator non-circular strip which has a-considerablemrea in contact .with the tapered-tube. vThis sectional-shape of reinforcement adds'to the longitudinal rigidity .of'thecore. 'rThat istosay, such flat reinforcement presents greater resistance to collapse inrthendirection of'theaxis ofithe core. :This'flat 'form ofn'einforcement has the added -advantage over reinforcements of circular cross-section such as "heretofore proposed, {that it can be readily covered with a layer of Water proofing material -(as-indicated in Fig. 4). *It is "ap parent that where the reinforcement is thin and'fiat ashere shown, it. doesnot require such a thick layer of tar, paint or .other water proofing compound'as would. benec essary in the case of a thick Wire-reinforce-v ment.

Though-I have described with great par- 7 ticularity the details of the embodiments of the:invention herein shown, it is not to'be construed that 1 'am limited ther'eto, as;

changes in arrangement and various modifications maybe made .without departing from the invention as defined in the appended claims.

whatfleclaimvisz 1. A hollow molding core adapted to 'formadining for a pipe or conduit com- ,prising atubeof flexible material having a spiral reinforcement and a layer of moisture resisting.materiahoutside of the reinforcement.

27A :hollow molding core ,adapted to '.,forn1.,a lining 'forca pipeor conduit comprising ia paper tube having an outervinetalhc spiral.reinforcementrand a layer of moisture resisting material covering the latter to protectl it"'fro1n the corrosive action of moist-ure. l i V 7 {EMA hollow core adapted i to form a per Vmanent lining for ,a conduit comprising a tube *ha-Ving ,an :outer spiral reinforcement of-a sec'tionalshape which presents a fiat face rto-thetube andcformed of a material of greaterstiffnessthanthat ofgsaid core, 7

and a coating of waterproofing material covering both .the ,tube and the reinforce- \ment. 7 c

A. .An ,article of v vmanufacture comprising a paperrtubelhaving a Waterproof coating con itsinneran'd outersurface and a metal- ,lic: reinforcement between the tube and the coating said tubebeing adapted to form a ,permanent lining ,for ,pipes or conduits.

5. I A, pipecor conduit comprising an outer 7 layer of cementitiousfl material andan inner lining .com-prisinga. tube .of fibrous material havingt-an outen reinforcement and a layer of waterproofing material :covering'both the 5' tube .and thesreinforcement.

-In witness awhereof, .I have hereunto signed myrname.

. THOMAS .E. MURRAY. 

